Monday, December 8, 2014

Abstract-Theoretical and Experimental Study on THz Generated by Photoconductive Antenna

THz (Terahertz or THz radiation, T-rays, referred to as THz) usually refers to the electromagnetic waves (1THz=1012Hz) of frequency at 0.1 TH2々10THz (wavelength of 3mm～30μm).Terahertz was in the transition zone from electronics to photonics and it also in the transition zone from the classical theory of macroscopic to the microscopic quantum theory, this particular location and there were many significantly different characteristics for millimeter waves and infared wave on transmission, scattering, reflection, absorption, penetration and so on, all the advantages above involved decided that terahertz has important scientific value and broad application prospects on object imaging, Medical diagnostics, Environmental monitoring, radio astronomy, broadband mobile communications, satellite communications and military radar.Firstly, it briefly introduced the main characteristics and applications of the THz wave, and there was an overview of current development status of foreign and domestic of THz Generated by Photoconductive Antenna.Secondly, generated from a photoconductive antenna terahertz starting the physical mechanism, the establishment of a THz photoconductive antenna to the current instantaneous impulse model, combined with small-aperture photoconductive antenna characteristics of a certain improvement of the model, according to Maxwell’s electromagnetic theory in detail derived THz near-field and far field expressions.Thirdly, according to the improved mathematical model, numerical simulation, respectively, and a detailed analysis of the biased Electric field, the pump laser power, pulse width, flux saturation effect and photoconductive antenna material carrier lifetime, carrier relaxation time and electrode gap on the pacific THz wave effect.At last, there was a experimental study on photoconductive antenna generating THz. Different chopper repetition frequency, laser pump power and bias voltage was applied to experiment, and there was a contrast and analysis on output power of THz, further experiments program was propose.